Hydro mechanical signaling often mediates the adaptive responses of vascular systems in response to ontogenetic changes in shape or size, or during reproduction, wound healing or tumor formation (i.e., changes in the environment extrinsic to the vascular system). Vascular transport is sensitive to variation in the environment because it is dynamically linked to food availability and vascular architecture (that conforms to the surface upon which it grows). In these organisms, hydromechanical signaling of colony morphogenesis could be similarly adaptive, allowing morphogenetic events to occur with great plasticity in response to c changing environment. The proposed research investigates this question by manipulating hydromechanical characteristics of vascular flow through manipulation of seawater viscosity and assaying the effects on colony development. The specific objectives are to: (1) develop a system to deliver a controlled quantity of homogenized food impregnated with 1 mum latex beads in small agar blocks, (2) establish the temporal patterns of stolen growth and polyp budding with respect to feeding time and maximal fluid transport, (3) determine the spatial pattern of mitosis of stolen (vascular tubes) cells along the stolen and the spacing of polyps. This proposal will test for the first time whether the relative investment in polyp and characteristics of vascular transport. The significance of such finding lies in the recognition that hydromechanical signaling in vascular systems may be a shared primitive character for all metazoans and consequently other model systems, like colonial hydrozoans, may serve fruitfully as alternative and less ethnically controversial models for the study of vascular function.